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name: nestjs-security description: Implement JWT authentication, RBAC guards, Helmet hardening, and Argon2 hashing in NestJS. Use when adding auth strategies, role-based access control, CSRF protection, or security headers. metadata: triggers: files: - '/*.guard.ts' - '/*.strategy.ts' - '/auth/' keywords: - Passport - JWT - AuthGuard - CSRF - Helmet

NestJS Security Standards

Priority: P0 (CRITICAL)

Workflow: Secure NestJS Application

1. Add Helmet — app.use(helmet()) in main.ts for HSTS, CSP headers.
2. Configure JWT strategy — Use passport-jwt with RS256; validate iss and aud claims.
3. Bind global AuthGuard — Register as APP_GUARD; use @Public() for open routes.
4. Add throttling — Enable @nestjs/throttler with Redis store for rate limiting.
5. Hash with Argon2id — Replace bcrypt with argon2.hash(password, { type: argon2.argon2id }).
6. Verify — Run npm audit --prod and test that unauthenticated requests return 401.

Global Auth Guard Example

See implementation examples

Argon2id Hashing Example

See implementation examples

Authentication (JWT)

• Strategy: Use @nestjs/passport with passport-jwt.
• Algorithm: Enforce RS256 (preferred) or HS256. Reject none.
• Claims: Validate iss and aud.
• Tokens: Short access (15m), Long httponly refresh (7d).
• MFA: Require 2FA for admin panels.

Authorization (RBAC)

• Deny by default: Bind AuthGuard globally (APP_GUARD).
• Bypass: Create @Public() decorator for open routes.
• Roles: Use Reflector.getAllAndOverride for Method/Class merge.

Cryptography

• Hashing: Use Argon2id, not Bcrypt. See implementation.
• Encryption: Use AES-256-GCM with KMS rotation. See implementation.

Hardening

• Helmet: Mandatory. Enable HSTS, CSP.
• CORS: Explicit origins only. No *.
• Throttling: Use Redis-backed @nestjs/throttler in production.
• CSRF: Required for cookie-based auth. See implementation.

Data Protection

• Sanitization: Use ClassSerializerInterceptor + @Exclude().
• Validation: ValidationPipe({ whitelist: true }) to prevent mass assignment.
• Audit: Log mutations (Who, What, When). See implementation.

Secrets Management

• CI/CD: Run npm audit --prod in pipelines.
• Runtime: Inject via vault (AWS Secrets Manager / HashiCorp Vault), not .env.

Anti-Patterns

• No Shadow APIs: Audit routes regularly; disable /docs in production.
• No SSRF: Allowlist domains for all outgoing HTTP requests.
• No SQLi: Use ORM; avoid raw query() with string concatenation.
• No XSS: Sanitize HTML input with dompurify.

References

• Implementation Examples
• common/security-standards